A soybean material such as soymilk, tofu and soybean protein isolate is used as a raw material of various kind of foods or beverages, for example, a milk substitute ingredient, a substitute ingredient for fermented dairy product, an egg yolk substitute ingredient, an ingredient for processed soy food, an ingredient for reducing serum cholesterol and an ingredient for improving renal function, in a food or beverage.
A Technology Concerning a Dairy Product Substitution in a Food
For the purpose of topping (decoration), nappe (surface coating), filling or kneading in confectionery, bread, dessert or the like, and for the purpose of adding taste in cooking, fresh cream or compound cream (mixture of milk fat and vegetable fat) is widely used in order to give a peculiar rich milk taste and a cooling feel in the mouth. Especially, fresh cream is an essential material for preparing confectionery and cooking due to its full-rich taste and milk taste. However, the fresh cream is relatively expensive and difficult for long storage, for example, it is necessary to use the fresh cream within 2 or 3 days after breaking the seal even in a refrigerator, and the fresh cream does not match a health trend due to its relatively high fat content such as 30 to 50 wt % of fat content. Therefore, a fresh cream substitute material which has a good taste and good handling property is desired.
As the above mentioned substitute material, application of tofu or soymilk is considered. Although a soybean-derived raw material-containing food or beverage such as confectionery, dessert, beverage, soup and sauce has a healthful image, it has peculiar taste of raw vegetation derived from soybean and it lacks rich and delicious taste. Therefore, there are high market needs to provide a soybean-derived raw material-containing food or beverage of which such a taste is improved.
As a method for improving such a peculiar taste derived from soybean, Patent Document 1 discloses a method for reducing a taste of raw vegetation derived from soybean as well as reducing a rough texture generated in a heat treatment step by adding a low sweetness sugar composition including trisaccharide or tetrasaccaride having branching structure to a soy food or beverage. Patent Document 2 discloses a sterilized soymilk having full (rich taste) and good taste obtained by a method including acting protein cross-linking enzyme to a soymilk or a soybean raw material during a step of preparing soymilk, and then subjecting to sterilization treatment. In addition, Patent Document 3 discloses a method for producing an acidic soymilk beverage including heating soymilk at 130 to 150° C. for several tens of seconds, and then acidifying by a lactic acid fermentation or adding an acidic substance, where the obtained acidic soymilk beverage has smooth texture and rich taste without unpleasant taste such as taste of raw vegetation and harsh taste peculiar to soybean.
A Technology Concerning a Fermented Dairy Product Substitution in a Food
Next, a fermented milk obtained by lactic fermentation of milk raw material is eaten itself as cheese or yogurt, or is used as main raw material or auxiliary raw material for topping (decoration), kneading, filling or nappe (surface coating), in a processed food such as confectionery, Japanese confectionery, bread, dessert, frozen dessert and beverage.
In addition, a fermented filled milk type emulsion prepared by blending vegetable fat as substitute for milk fat while skim milk or the like is used as a milk protein, and then fermenting, is also known (Patent Documents 4 to 7). This emulsion is also used in the above mentioned processed food in the same purpose of the fermented milk, and adds various functions and additional value to the processed food to contribute to a development of food industry.
On the other hand, a fermented soybean material using a soybean protein as a protein source is expected as a plant-derived fermented material which is good for health because milk fat is not used, and a part of the material is considered as a substitute for conventional fermented dairy product such as cheese and yogurt. A soybean material such as soymilk, soybean protein isolate and soy flour is used as a raw material which contains a soybean protein.
A Technology Concerning an Egg Yolk Substitution in a Food
Next, an egg yolk is widely used to various foods such as seasoning, daily dish and confectionery because it has excellent feature in its function, nutritive value and the like. However, in recent years, an ingestion of egg yolk which has high cholesterol content tends to be avoided due to a growing awareness of health trends. Moreover, in recent years, instability of supply and rise in the price of egg etc. by the influences of a natural disaster and avian infections etc. are feared although an egg has been originally said as an “exemplary model of prices”.
Various considerations concerning an egg substitute food have been conducted because of such a background. For example, an egg-like food prepared by using a dried egg white particle and dried pumpkin yellow particle, and omelet as a usage example are suggested (Patent Document 9). In addition, as a technology of using a soybean material, a technology related to a low cholesterol egg substitute composition including soybean protein and egg white protein, and baked product (pound cake) as an application example (Patent Document 10) and a technology related to an emulsion including concentrated soymilk and mayonnaise-like food as an application example prepared by using the emulsion (Patent Document 11) are disclosed. Further, a technology related to an egg substitute food prepared by using an isolated whey protein and examples of its application such as sponge cake and custard pudding are disclosed (Patent Document 12).
A Technology Concerning a Processed Soy Food
Next, tofu, yuba (bean curd skin) and abura-age (deep-fried thin bean curd) and the like, which are prepared from soybean as a raw material, are traditional processed soy foods that have long been eaten in Japan. Generally, various processed soy foods are prepared from “soymilk” as a starting raw material, where the soymilk is obtained by adding water to soybean, and then grinding to obtain “go” (soybean slurry), optionally heating the “go”, and then removing okara (bean curd refuse) by centrifugation or filtration. Tofu is a typical example of the processed soy food, and various kinds of tofu are manufactured through a step of coagulating soymilk with a coagulant agent such as brine. Tofu obtained by cutting a curd which is obtained by coagulating soymilk with a coagulant agent and then immersing the cut curd in water is called as “silken tofu”. In addition, tofu obtained by breaking the curd and then dehydrating and molding the curd with a filter cloth is called as “cotton tofu (firm tofu)”. These tofus are comparatively firm and shape retaining gels. Recently, these tofus are marketed as filled tofu sealed in a plastic container. Although each tofu has different hardness, these tofus share an appropriate hardness and light gel texture. These traditional tofus have long been liked and are indispensable in Japanese eating habits. On the other hand, differentiated and high-value added novel tofu compared to traditional tofu is desired because the traditional tofu is cheap and has low-margin from an industrial viewpoint. Therefore, yose-tofu that a bean curd is directly put into a container without molding and thereby breaking a part of construction of curd and being indeterminate form is marketed.
In addition, it is required to develop differentiated and high-value added novel product compared to traditional product not only for tofu, but also for other processed soy foods such as abura-age, ganmodoki (deep-fried bean curd containing bits of various kinds of vegetables), atsu-age (deep-fried tofu) and yuba.
Under the circumstances, development of tofus having various kind of characteristics compared to traditional tofu has been conducted. For example, Patent Document 13 describes a tofu paste which is obtained by mixing a thickening and gelling agent, oligosaccharide and starch to tofu, mixing the mixture with high-speed cutter, heating and then cooling the mixture. In addition, Patent Document 14 describes a tofu-containing fat composition which is obtained by adding tofu which is processed to paste form into aqueous phase, and then emulsifying to water-in-oil emulsion.
Further, Patent Document 15 describes a method of producing soybean protein curd including preparing a soymilk from soybean having reduced NSI with a heat treatment, subjecting the soymilk to acidic precipitation to concentrate protein, neutralizing to re-dissolve the protein, and then adding coagulant agent and being heat-coagulated to obtain the soybean protein curd having cream-like texture.
A Technology Concerning a Reduction of Serum Cholesterol and an Improvement of Renal Function
Next, there is Patent Document 16 as patent application relating to a composition for reducing serum cholesterol, where the composition is prepared from soybean as a raw material. In addition, there is Patent Document 17 as patent application relating to a powdered material for reducing blood cholesterol. Further, there is Patent Document 18 as patent application relating to a fractionated soybean protein material. Moreover, Patent Document 19 describes a soybean protein material for patients with renal disease, where the material is prepared from soybean as a raw material.